Is lemon juice safe for brightening the skin?

Social media has advanced our interest for DIY beauty more than ever before. Pinterest, Instagram, Youtube and others provide us with endless amounts of homemade face mask recipes, scalp treatments and weird hacks, promising to banish our skin woes forever. 

Lemon juice is one of the most common ingredients I see, as the creators claim how a natural lemon will to help lighten the skin and prevent skin sagging and wrinkles.

Yet the other half of the internet and social accounts (mostly industry professionals) strongly advise against it and list dangerous potential side effects. 

Are lemons safe to use directly on the skin? Can it actually improve our skin health, or is this just another bizarre beauty fad? Scroll down to find out if and how lemon juice can be used to help brighten your skin, and what kind of results to expect.


Why lemon? 

The lemon, aka Citrus Limon is a bright yellow fruit and used around the world for cooking and non-cooking purposes. 

Its exact origin is unknown however it is believed to come from subtropical Southeast Asia.

Lemon has shown to have anticancer and antibacterial activities and also used for medicinal purposes to purify the blood, to treat insomnia, travel sickness and asthma. Lemon has also been used as an essential oil since the 18th century to also treat anxiety, hypertension and rheumatism. 

In skincare, lemon-derived products have been credited for helping to manage acne prone skin.

Lemon essential oil is used in shampoos, toothpastes, disinfectants, topical ointments.

Different parts of the lemon are used for different things in cosmetic products, for example Citrus Limon peel extract works as an emollient, conditioner and protector in cosmetics, whereas the juice extract performs as a tonic. 


The reason for using lemon in skincare is because of three glow-inducing ingredients that is used often in cosmetic formulations:

Vitamin C

A potent antioxidant that helps to neutralise free radical production in the skin, thus reducing pigmentation and inflammation.

Citric acid

Is an Alpha Hydroxy Acid (AHA) which means it dissolves the glue that binds the dead skin cells to the surface of the skin. AHAs not only exfoliate the surface but encourage cellular turnover, promoting the growth of healthy, new cells.

B3 

Niacinamide is an active, water-soluble form of the nutrient b3. In the body, B3 is essential for good health and something we get from our diet. In skincare, vitamin b3 can help to reduce breakouts, hyperpigmentation, rosacea, and soften the appearance of fine lines. It is also known for its moisturising qualities as well.

What results can you expect from using lemon juice on the skin?

Despite the fact that lemons are home to some superstar skincare ingredients, it doesn’t mean you should be rushing to cut a lemon and stick it on your face.

Firstly, lemons contain many other chemicals besides the three (Vit C, B3 and citric acid) we have spoken about. Fruits are individual in these measurements, the composition depends on a lot of things including where the plant is grown and the temperature of its environment, how ripe the fruit is and the type of lemon.

Secondly, you will have to squeeze a lot of lemons to achieve the same percentages of Vitamin C, B3 and citric acid as when they are formulated in skincare. My limited expertise in science makes it difficult for me to explain why in my own words, so I must credit Michelle on her iconic Labmuffin blog once again, for clearing this one up for the online skincare community. 

“...In a typical sample of lemon juice, you’ll find 0.04% ascorbic acid, 5% citric acid and 0.0001% niacin.
Normally in skincare, serums will have 5-15% ascorbic acid, 2-15% AHA, and 2-10% niacinamide. So in lemon juice, you only really get a decent amount of citric acid.”

Is lemon juice safe for the skin?

On Michelle’s blog post, amongst others discussing this same topic, have all mentioned the risk of photosensitivity when using lemon juice on the skin.

Lemon contains photosensitive agents called furanocoumarins (or furocoumarins) and psoralens which can lead to a strong reaction called Phytophototoxic dermatitis. 

A 2017 report explained the symptoms of this aggressive reaction: 

“Generally, erythema occurs within 24 hours after initial furocoumarin contact, which may progress to blistering or tense and painful bullae formation. This clinical progression eventually develops into hyperpigmentation of the affected area.”

Often confused for skin burns because of the intense blistering this reaction causes, phytophototoxic dermatitis not only damages cell DNA and membranes leading to cell death, but also cause patches of hyperpigmentation in the affected area.

Another reason why fresh lemon juice is not ideal to apply directly onto the skin is because of its PH level. Maintaining a healthy PH is vital for:

  • Skin barrier function

  • Skin integrity

  • Antimicrobial purposes

Human skin maintains a PH of 4 to 5 whereas lemon juice has a PH of 2.

Applying a highly acidic substance to the face can compromise the barrier function, which may lead to skin irritation, sensitisation and inflammation.

There is enough evidence to show how lemon essential oils can decrease free radicals, manage pigmentation, increase penetration in products, as well as working as a preservative. However there isn’t any evidence to show how a natural lemon will do the same when applied to the skin. 

A lot of the blog posts, churned online content and glossy magazines that mention the ‘studies’ surrounding lemon juice and the skin, mostly only refer to the individual ingredients themselves. 

There is no scientific data to be found that proves freshly squeezed lemon juice provides any real benefit when applied to the skin. 

Despite Dr Pimple Popper and Bella Thorne swearing by using lemons in their homemade masks, it’s just not something that I would recommend. The risk is too high, and the outcome too little when you look at the percentages of key ingredients from a fresh lemon, compared to a skincare bottle.

Skincare serums that use ingredients derived from the lemon will be formulated with other ingredients to help treat your skin concerns, and tested enough to guarantee lesser risk of reaction. 

If hyperpigmentation is a concern, the worst thing you can do is apply fresh lemon to the affected area. There is enough data out there to tell us that Phytophototoxic dermatitis is a real thing, and a common reaction when skin is applied to UV radiation following exposure to citrus fruits. 

If you find yourself still wanting to squeeze some fresh lemon into your at-home, honey facial mask then at least ensure it is only a few drops. Apply the concoction in the evening, and wear a broad-spectrum SPF during the weeks that follow. Consider other skin brightening ingredients like these in your skincare routine instead.